A worldwide survey of more than 136,000 people in 132 countries included questions about happiness and income, and the results reveal that although life satisfaction usually rises with income, positive feelings don't necessarily follow, researchers report.

The findings, from an analysis of data gathered in the first Gallup World Poll, appear this month in the Journal of Personality and Social Psychology.

"The public always wonders: Does money make you happy?" said University of Illinois professor emeritus of psychology Ed Diener, a senior scientist with the Gallup Organization. "This study shows that it all depends on how you define happiness, because if you look at life satisfaction, how you evaluate your life as a whole, you see a pretty strong correlation around the world between income and happiness," he said. "On the other hand, it's pretty shocking how small the correlation is with positive feelings and enjoying yourself."

The Gallup World Poll conducted surveys on a wide range of subjects in a representative sample of people from 132 countries from 2005 to 2006. The poll used telephone surveys in more affluent areas, and door-to-door interviews in rural or less-developed regions. The countries surveyed represent about 96% of the world's population, the researchers report, and reflect the diversity of cultural, economic and political realities around the globe.

This "first representative sample of planet earth," the authors wrote, "was used to explore the reasons why happiness is associated with higher income." The researchers were able to look at a long list of attributes of respondents, including their income and standard of living, whether their basic needs for food and shelter were met, what kinds of conveniences they owned and whether they felt their psychological needs were satisfied.

The surveys included a global life evaluation, which asked respondents to rate their lives on a scale that ranged from zero (worst possible life) to 10 (best possible life). Participants also answered questions about positive or negative emotions experienced the previous day. And the poll asked respondents whether they felt respected, whether they had family and friends they could count on in an emergency, and how free they felt to choose their daily activities, learn new things or do "what one does best."

Similar to previous studies, the new analysis found that life evaluation, or life satisfaction, rises with personal and national income. But positive feelings, which also increase somewhat as income rises, are much more strongly associated with other factors, such as feeling respected, having autonomy and social support, and working at a fulfilling job.

This is the first happiness study of the world to differentiate between life satisfaction, the philosophical belief that your life is going well, and the day-to-day positive or negative feelings that one experiences, Diener said.

"Everybody has been looking at just life satisfaction and income," he said. "And although it is true that getting richer will make you more satisfied with your life, it may not have the big impact we thought on enjoying life." Weiting Ng, of the Singapore Institute of Management; and James Harter and Raksha Arora, of The Gallup Organization, were co-authors on the study with Diener.